Major planner/optimizer revision: get rid of PathOrder node type,

store all ordering information in pathkeys lists (which are now lists of
lists of PathKeyItem nodes, not just lists of lists of vars).  This was
a big win --- the code is smaller and IMHO more understandable than it
was, even though it handles more cases.  I believe the node changes will
not force an initdb for anyone; planner nodes don't show up in stored
rules.

Author: tglsfdc

src/backend/nodes/copyfuncs.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.90 1999/08/09 06:20:23 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.91 1999/08/16 02:17:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1030,10 +1030,6 @@ _copyRelOptInfo(RelOptInfo *from)
 		newnode->indexkeys[len] = 0;
 	}
 
-	newnode->relam = from->relam;
-	newnode->indproc = from->indproc;
-	Node_Copy(from, newnode, indpred);
-
 	if (from->ordering)
 	{
 		for (len = 0; from->ordering[len] != 0; len++)
@@ -1044,6 +1040,10 @@ _copyRelOptInfo(RelOptInfo *from)
 		newnode->ordering[len] = 0;
 	}
 
+	newnode->relam = from->relam;
+	newnode->indproc = from->indproc;
+	Node_Copy(from, newnode, indpred);
+
 	Node_Copy(from, newnode, restrictinfo);
 	Node_Copy(from, newnode, joininfo);
 	Node_Copy(from, newnode, innerjoin);
@@ -1061,8 +1061,6 @@ _copyRelOptInfo(RelOptInfo *from)
 static void
 CopyPathFields(Path *from, Path *newnode)
 {
-	newnode->pathtype = from->pathtype;
-
 	/*
 	 * Modify the next line, since it causes the copying to cycle (i.e.
 	 * the parent points right back here! -- JMH, 7/7/92. Old version:
@@ -1072,32 +1070,9 @@ CopyPathFields(Path *from, Path *newnode)
 
 	newnode->path_cost = from->path_cost;
 
-	newnode->pathorder = makeNode(PathOrder);
-	newnode->pathorder->ordtype = from->pathorder->ordtype;
-	if (from->pathorder->ordtype == SORTOP_ORDER)
-	{
-		int			len,
-					i;
-		Oid		   *ordering = from->pathorder->ord.sortop;
-
-		if (ordering)
-		{
-			for (len = 0; ordering[len] != 0; len++)
-				;
-			newnode->pathorder->ord.sortop = (Oid *) palloc(sizeof(Oid) * (len + 1));
-			for (i = 0; i < len; i++)
-				newnode->pathorder->ord.sortop[i] = ordering[i];
-			newnode->pathorder->ord.sortop[len] = 0;
-		}
-	}
-	else
-		Node_Copy(from, newnode, pathorder->ord.merge);
+	newnode->pathtype = from->pathtype;
 
 	Node_Copy(from, newnode, pathkeys);
-
-	newnode->outerjoincost = from->outerjoincost;
-
-	newnode->joinid = listCopy(from->joinid);
 }
 
 /* ----------------
@@ -1135,32 +1110,20 @@ _copyIndexPath(IndexPath *from)
 	 */
 	newnode->indexid = listCopy(from->indexid);
 	Node_Copy(from, newnode, indexqual);
-
-	if (from->indexkeys)
-	{
-		int			i,
-					len;
-
-		for (len = 0; from->indexkeys[len] != 0; len++)
-			;
-		newnode->indexkeys = (int *) palloc(sizeof(int) * (len + 1));
-		for (i = 0; i < len; i++)
-			newnode->indexkeys[i] = from->indexkeys[i];
-		newnode->indexkeys[len] = 0;
-	}
+	newnode->joinrelids = listCopy(from->joinrelids);
 
 	return newnode;
 }
 
 /* ----------------
- *		CopyNestPathFields
+ *		CopyJoinPathFields
  *
- *		This function copies the fields of the NestPath node.  It is used by
- *		all the copy functions for classes which inherit from NestPath.
+ *		This function copies the fields of the JoinPath node.  It is used by
+ *		all the copy functions for classes which inherit from JoinPath.
  * ----------------
  */
 static void
-CopyNestPathFields(NestPath *from, NestPath *newnode)
+CopyJoinPathFields(JoinPath *from, JoinPath *newnode)
 {
 	Node_Copy(from, newnode, pathinfo);
 	Node_Copy(from, newnode, outerjoinpath);
@@ -1181,7 +1144,7 @@ _copyNestPath(NestPath *from)
 	 * ----------------
 	 */
 	CopyPathFields((Path *) from, (Path *) newnode);
-	CopyNestPathFields(from, newnode);
+	CopyJoinPathFields((JoinPath *) from, (JoinPath *) newnode);
 
 	return newnode;
 }
@@ -1200,7 +1163,7 @@ _copyMergePath(MergePath *from)
 	 * ----------------
 	 */
 	CopyPathFields((Path *) from, (Path *) newnode);
-	CopyNestPathFields((NestPath *) from, (NestPath *) newnode);
+	CopyJoinPathFields((JoinPath *) from, (JoinPath *) newnode);
 
 	/* ----------------
 	 *	copy the remainder of the node
@@ -1227,76 +1190,32 @@ _copyHashPath(HashPath *from)
 	 * ----------------
 	 */
 	CopyPathFields((Path *) from, (Path *) newnode);
-	CopyNestPathFields((NestPath *) from, (NestPath *) newnode);
+	CopyJoinPathFields((JoinPath *) from, (JoinPath *) newnode);
 
 	/* ----------------
 	 *	copy remainder of node
 	 * ----------------
 	 */
 	Node_Copy(from, newnode, path_hashclauses);
-	Node_Copy(from, newnode, outerhashkeys);
-	Node_Copy(from, newnode, innerhashkeys);
 
 	return newnode;
 }
 
 /* ----------------
- *		_copyOrderKey
+ *		_copyPathKeyItem
  * ----------------
  */
-static OrderKey *
-_copyOrderKey(OrderKey *from)
+static PathKeyItem *
+_copyPathKeyItem(PathKeyItem *from)
 {
-	OrderKey   *newnode = makeNode(OrderKey);
+	PathKeyItem   *newnode = makeNode(PathKeyItem);
 
 	/* ----------------
 	 *	copy remainder of node
 	 * ----------------
 	 */
-	newnode->attribute_number = from->attribute_number;
-	newnode->array_index = from->array_index;
-
-	return newnode;
-}
-
-
-/* ----------------
- *		_copyJoinKey
- * ----------------
- */
-static JoinKey *
-_copyJoinKey(JoinKey *from)
-{
-	JoinKey    *newnode = makeNode(JoinKey);
-
-	/* ----------------
-	 *	copy remainder of node
-	 * ----------------
-	 */
-	Node_Copy(from, newnode, outer);
-	Node_Copy(from, newnode, inner);
-
-	return newnode;
-}
-
-/* ----------------
- *		_copyMergeOrder
- * ----------------
- */
-static MergeOrder *
-_copyMergeOrder(MergeOrder *from)
-{
-	MergeOrder *newnode = makeNode(MergeOrder);
-
-	/* ----------------
-	 *	copy remainder of node
-	 * ----------------
-	 */
-	newnode->join_operator = from->join_operator;
-	newnode->left_operator = from->left_operator;
-	newnode->right_operator = from->right_operator;
-	newnode->left_type = from->left_type;
-	newnode->right_type = from->right_type;
+	Node_Copy(from, newnode, key);
+	newnode->sortop = from->sortop;
 
 	return newnode;
 }
@@ -1315,83 +1234,16 @@ _copyRestrictInfo(RestrictInfo *from)
 	 * ----------------
 	 */
 	Node_Copy(from, newnode, clause);
-
 	newnode->selectivity = from->selectivity;
-
-	Node_Copy(from, newnode, indexids);
-	Node_Copy(from, newnode, mergejoinorder);
+	Node_Copy(from, newnode, subclauseindices);
+	newnode->mergejoinoperator = from->mergejoinoperator;
+	newnode->left_sortop = from->left_sortop;
+	newnode->right_sortop = from->right_sortop;
 	newnode->hashjoinoperator = from->hashjoinoperator;
 
 	return newnode;
 }
 
-/* ----------------
- *		CopyJoinMethodFields
- *
- *		This function copies the fields of the JoinMethod node.  It is used by
- *		all the copy functions for classes which inherit from JoinMethod.
- * ----------------
- */
-static void
-CopyJoinMethodFields(JoinMethod *from, JoinMethod *newnode)
-{
-	Node_Copy(from, newnode, jmkeys);
-	Node_Copy(from, newnode, clauses);
-	return;
-}
-
-/* ----------------
- *		_copyJoinMethod
- * ----------------
- */
-static JoinMethod *
-_copyJoinMethod(JoinMethod *from)
-{
-	JoinMethod *newnode = makeNode(JoinMethod);
-
-	CopyJoinMethodFields(from, newnode);
-
-	return newnode;
-}
-
-/* ----------------
- *		_copyHashInfo
- * ----------------
- */
-static HashInfo *
-_copyHashInfo(HashInfo *from)
-{
-	HashInfo   *newnode = makeNode(HashInfo);
-
-	/* ----------------
-	 *	copy remainder of node
-	 * ----------------
-	 */
-	CopyJoinMethodFields((JoinMethod *) from, (JoinMethod *) newnode);
-	newnode->hashop = from->hashop;
-
-	return newnode;
-}
-
-/* ----------------
- *		_copyMergeInfo
- * ----------------
- */
-static MergeInfo *
-_copyMergeInfo(MergeInfo *from)
-{
-	MergeInfo  *newnode = makeNode(MergeInfo);
-
-	/* ----------------
-	 *	copy remainder of node
-	 * ----------------
-	 */
-	CopyJoinMethodFields((JoinMethod *) from, (JoinMethod *) newnode);
-	Node_Copy(from, newnode, m_ordering);
-
-	return newnode;
-}
-
 /* ----------------
  *		_copyJoinInfo
  * ----------------
@@ -1408,9 +1260,6 @@ _copyJoinInfo(JoinInfo *from)
 	newnode->unjoined_relids = listCopy(from->unjoined_relids);
 	Node_Copy(from, newnode, jinfo_restrictinfo);
 
-	newnode->mergejoinable = from->mergejoinable;
-	newnode->hashjoinable = from->hashjoinable;
-
 	return newnode;
 }
 
@@ -1756,27 +1605,12 @@ copyObject(void *from)
 		case T_HashPath:
 			retval = _copyHashPath(from);
 			break;
-		case T_OrderKey:
-			retval = _copyOrderKey(from);
-			break;
-		case T_JoinKey:
-			retval = _copyJoinKey(from);
-			break;
-		case T_MergeOrder:
-			retval = _copyMergeOrder(from);
+		case T_PathKeyItem:
+			retval = _copyPathKeyItem(from);
 			break;
 		case T_RestrictInfo:
 			retval = _copyRestrictInfo(from);
 			break;
-		case T_JoinMethod:
-			retval = _copyJoinMethod(from);
-			break;
-		case T_HashInfo:
-			retval = _copyHashInfo(from);
-			break;
-		case T_MergeInfo:
-			retval = _copyMergeInfo(from);
-			break;
 		case T_JoinInfo:
 			retval = _copyJoinInfo(from);
 			break;